1. Field of the Invention
This invention relates generally to electronic recording devices and multiple sensors for measuring various parameters at locations remote from the recording device. The present invention is particularly adapted for using multiple sensors to measure various parameters at a downhole location within the bore of an oil or gas well and to record each parameter at the well surface. However, the invention can be used to measure various parameters at the well surface or to measure parameters in other types of wells.
2. Description of the Prior Art
For many years, operators of oil and gas wells have been interested in measuring various physical parameters associated with each well in order to understand the characteristics of the underground hydrocarbon producing formation and to optimize the production of hydrocarbons from each well. Some of the more frequently measured parameters are:
a. bottom hole pressure and surface pressure when the well is both flowing and shut in; PA0 b. flow rate versus pressure and direction of fluid flow; PA0 c. pressure versus time both during pressure buildup after shutting in a well and pressure drawdown after resuming flow; PA0 d. oil versus gas ratio in the production fluid; and PA0 e. the depth at which each parameter is measured.
U.S. Pat. No. 4,107,697 titled Pressure Recorder with Power Conservation Means and U.S. Pat. No. 4,161,782 titled Microprocessor Computerized Pressure/Temperature/Time Down-Hole Recorder disclose well tools which can measure and record some of these parameters. Both patents are incorporated by reference for all purposes within this application.